1. Field of the Invention
The present invention relates to a semiconductor power module of a power converter used by general industrial machines and electric power systems, and to a power converter having such a power module.
2. Description of the Related Art
JP-A-6-70553 discloses a conventional power converter which has a function of diagnosing the life of the converter by storing electrical characteristics such as currents and voltages and maintenance history. According to this conventional technique, the life of a power converter is diagnosed by storing calculation results used for controlling the converter or maintenance history in a control unit of the power converter.
Even if information of use history and the like of a semiconductor power module is to be stored in the control unit, this information of use history and the like cannot be obtained from the semiconductor power module alone. Therefore, if a defective component other than the semiconductor power module is found in a power converter, the use history already stored is not inherited, and in some cases, the semiconductor power module as well as the defective component is replaced at the same time. Since the semiconductor power module is not used effectively but dumped, the amount of industrial wastes increases, which is not desired from the viewpoint of environments.
Each semiconductor power module has generally its own manufacture serial number. If a number of power semiconductor modules are to be managed by using only manufacture serial numbers, it takes time and labor for this management. In some cases, modules still not used and modules temporarily used cannot be distinguished.